1. Field of the Invention
Aspects of the present invention relate to an organic light emitting device, and more particularly, to an organic light emitting device with improved driving voltage, light-emitting efficiency and lifetime by enhancing the electron injection abilities by incorporating a novel material for forming an electron transport layer.
2. Description of the Related Art
Organic light-emitting devices are self-emissive display devices that have drawn a large amount of attention due to a wide viewing angle, superior contrast, and quick response time.
An organic light emitting device typically comprises an anode, a cathode, and an organic light emitting layer between the anode and the cathode. As a non-limiting example, an organic light emitting device may be produced by forming an anode composed of a transparent conducting material such as ITO (indium tin oxide) on a glass substrate, and depositing a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, and a cathode thereon.
In the organic light emitting device composed of deposited layers as described above, when direct-current voltage is applied between the anode and the cathode, a hole is injected from the anode, and electrons are injected from the cathode. The hole is transported to the emission layer through the hole injection layer and the hole transport layer, and electrons are transported to the emission layer through the electron transport layer. Then, light is emitted through the recoupling of the holes and the electrons in the emission layer.
A material such as tris-8-hydroxyquinolato aluminum (Alq3) is generally used to form the electron transport layer. However, when an electron transport layer is formed using electron transport materials known to date, the voltage typically must be increased to achieve a given luminance due to barriers formed during electron injection. Therefore, the development of a new electron transport material is desirable.